Defibrillators

ABSTRACT

Defibrillators are provided that include a graphical user interface to assist a caregiver in administering resuscitation.

TECHNICAL FIELD

[0001] This invention relates to defibrillators, and more particularlyto automatic external defibrillators (AEDs).

BACKGROUND

[0002] Resuscitation treatments for patients suffering from cardiacarrest generally include clearing and opening the patient's airway,providing rescue breathing for the patient, and applying chestcompressions to provide blood flow to the victim's heart, brain andother vital organs. If the patient has a shockable heart rhythm,resuscitation also may include defibrillation therapy.

[0003] There are many different kinds of abnormal heart rhythms, some ofwhich can be treated by defibrillation therapy (“shockable rhythms”) andsome which cannot (non-shockable rhythms”). For example, most ECGrhythms that produce significant cardiac output are considerednon-shockable (examples include normal sinus rhythms, certainbradycardias, and sinus tachycardias). There are also several abnormalECG rhythms that do not result in significant cardiac output but arestill considered non-shockable, since defibrillation treatment isusually ineffective under these conditions. Examples of thesenon-shockable rhythms include asystole, electromechanical disassociationand other pulseless electrical activity. Although a patient cannotremain alive with these non-viable, non-shockable rhythms, applyingshocks will not help convert the rhythm. The primary examples ofshockable rhythms, for which the caregiver should performdefibrillation, include ventricular fibrillation, ventriculartachycardia, and ventricular flutter.

[0004] After using a defibrillator to apply one or more shocks to apatient who has a shockable ECG rhythm, the patient may neverthelessremain unconscious, in a shockable or non-shockable, perfusing ornon-perfusing rhythm. If a non-perfusing rhythm is present, thecaregiver may then resort to performing CPR for a period of time inorder to provide continuing blood flow and oxygen to the patient'sheart, brain and other vital organs. If a shockable rhythm continues toexist or develops during the delivery of CPR, further defibrillationattempts may be undertaken following this period of cardiopulmonaryresuscitation. As long as the patient remains unconscious and withouteffective circulation, the caregiver can alternate between use of thedefibrillator (for analyzing the electrical rhythm and possibly applyinga shock) and performing cardiopulmonary resuscitation (CPR). CPRgenerally involves a repeating pattern of five or fifteen chestcompressions followed by a pause during which two rescue breaths aregiven.

[0005] Defibrillation can be performed using an AED. The American HeartAssociation, European Resuscitation Council, and other similar agenciesprovide protocols for the treatment of victims of cardiac arrest thatinclude the use of AEDs. These protocols define a sequence of steps tobe followed in accessing the victim's condition and determining theappropriate treatments to be delivered during resuscitation. Caregiverswho may be required to use an AED are trained to follow these protocols.

[0006] Most automatic external defibrillators are actuallysemi-automatic external defibrillators (SAEDs), which require thecaregiver to press a start or analyze button, after which thedefibrillator analyzes the patient's ECG rhythm and advises thecaregiver to provide a shock to the patient if the electrical rhythm isshockable. The caregiver is then responsible for pressing a controlbutton to deliver the shock. Following shock delivery, the SAED mayreanalyze the patient's ECG rhythm, automatically or manually, andadvise additional shocks or instruct the caregiver to check the patientfor signs of circulation (indicating that the defibrillation treatmentwas successful or that the rhythm is non-shockable) and to begin CPR ifcirculation has not been restored by the defibrillation attempts. Fullyautomatic external defibrillators, on the other hand, do not wait foruser intervention before applying defibrillation shocks. As used below,automatic external defibrillators (AED) include semi-automatic externaldefibrillators (SAED).

[0007] Both types of defibrillators typically provide an auditory “standclear” warning before beginning ECG analysis and/or the application ofeach shock. The caregiver is then expected to stand clear of the patient(i.e. stop any physical contact with the patient) and may be required topress a button to deliver the shock. The controls for automatic externaldefibrillators are typically located on a resuscitation control box.

[0008] AEDs are typically used by trained medical or paramediccaregivers, such as physicians, nurses, emergency medical technicians,fire department personnel, and police officers. The ready availabilityof on-site AEDs and caregivers trained to operate them is importantbecause a patient's chances of survival from cardiac arrest decrease byapproximately 10% for each minute of delay between occurrence of thearrest and the delivery of defibrillation therapy. .

[0009] Trained lay caregivers are a new group of AED operators. Forexample, spouses of heart attack victims may become trained as laycaregivers. Lay caregivers rarely have opportunities to defibrillate ordeliver CPR, and thus they can be easily intimidated by an AED during amedical emergency. Consequently, such lay providers may be reluctant topurchase or use AEDs when needed, or might tend to wait for an ambulanceto arrive rather than use an available AED, out of concern that the layprovider might do something wrong.

[0010] Some trained medical providers, e.g., specialists such asobstetricians, dermatologists, and family care practitioners, alsorarely have the opportunity to perform CPR and/or defibrillate, and thusmay be uneasy about doing so. Concerns about competence are exacerbatedif training is infrequent, leading the caregiver to worry that he or shemay not be able to remember all of the recommended resuscitationprotocol steps and/or their correct sequence.

[0011] Similarly, both medical and lay caregivers may be hesitant toprovide CPR and rescue breathing, or may be unsure when these stepsshould be performed, particularly if their training is infrequent andthey rarely have the opportunity to use it.

SUMMARY

[0012] The invention provides a graphical user interface for use with anAED. The graphical user interface includes a set of graphics thatclearly indicate the steps that should be performed by a trainedcaregiver administering resuscitation to a victim of cardiac arrest. Thegraphics, which may be accompanied by audio prompts and/or othervisually displayed messages, provide visual reminders that will assistand encourage trained caregivers who might not otherwise feel competentto perform cardiac resuscitation including the use of an AED. In thecase of caregivers who are confident of their training and skills, thevisual prompts may aid the caregiver in more quickly and efficientlyperforming the required steps in the resuscitation sequence.

[0013] In one aspect, the invention features a defibrillator including:(a) electrodes configured to be attached to a patient, to acquire dataindicative of the patient's heart rhythm and to deliver a defibrillatingshock if appropriate; (b) a defibrillator control box connected to theelectrodes; and (c) on a portion of the defibrillator control box, aseries of graphics configured to prompt a caregiver to perform asequence of steps appropriate for treating a victim of suspected cardiacarrest.

[0014] Some implementations of the invention may include one or more ofthe following features. The graphics include one or more of thefollowing pictures: a picture configured to prompt the caregiver tocheck the patient for responsiveness, a picture configured to prompt thecaregiver to call for emergency assistance, a picture configured toprompt the caregiver to open the patient's airway, a picture configuredto prompt the caregiver to check the patient's pulse, a pictureconfigured to prompt the caregiver to attach the electrodes to thepatient, a picture configured to prompt the caregiver to stand clear ofthe patient, a picture configured to prompt the caregiver to press atreatment button to cause the defibrillator to administer adefibrillating shock, and a picture configured to prompt the caregiverto perform CPR. Preferably, the pictures illustrate how the steps are tobe performed, e.g., how to open the patient's airway, where theelectrodes should be attached, and how to perform chest compressions andrescue breathing.

[0015] Generally, if the defibrillator is an SAED, the defibrillatorwill further include a treatment button configured to be pressed by thecaregiver to cause the defibrillator to administer a defibrillatingshock. The location of the treatment button may be indicated by agraphic, e.g., a heart symbol.

[0016] In some implementations, the defibrillator further includes alight source associated with each of the graphics in the series. Thedefibrillator may include electronics configured to sequentiallyilluminate the light sources. The sequential illumination may becontrolled by electronics configured to measure the time elapsed fromthe time at which the caregiver turned the power on to activate thedefibrillator, at least some of the light sources being sequentiallyilluminated based on the elapsed time. Alternatively, or in addition,sequential illumination may be controlled by electronics configured tobe preprogrammed with times for the illumination of the light sources,at least some of the times being based on the time elapsed from (a) thetime at which the previous light source in the sequence was firstilluminated or (b) the time when a shock was delivered to the patient.The sequential illumination of some of the light sources may becontrolled by electronics configured to acquire data from theelectrodes, at least some of the light sources being sequentiallyilluminated based on the data acquired from the electrodes. The lightsources may be illuminated based on an algorithm, e.g., an algorithmthat takes into account one or more of the following items of data: (a)the time elapsed from the time at which the previous light source in thesequence was first illuminated, and/or (b) the time elapsed from thelast time a shock was delivered to the patient, and/or (c) the resultsof ECG analysis.

[0017] In some implementations, the defibrillator also includeselectronics configured to provide audio prompts to the caregiver. Theaudio prompts may be timed in any of the manners described above withregard to the sequential illumination of the light sources. Generally,the audio prompts are associated with the series of graphics and aregiven sequentially to guide the caregiver through the sequence of steps,and the audio prompts are also associated with the sequentialillumination of the light sources.

[0018] At least some of the graphics may be provided on a cover portionof the defibrillator control box. These graphics may be provided on theinside and/or outside of the cover. If the graphics are provided on theoutside of the cover, they may include a picture indicating that thecover should be removed from the defibrillator. The cover may include aspace provided for local emergency information, e.g., a window behindwhich a card bearing local emergency information can be placed.

[0019] The graphics may be provided in any desired manner, for example,in the form of backlit, translucent images, as an electronic display, orin the form of a decal.

[0020] In another aspect, the invention features a system for promptinga caregiver in a resuscitation sequence for a patient who may besuffering from cardiac arrest. The system includes: (a) electrodesconstructed to acquire data, indicative of the heart rhythm of thepatient and indicative of whether the electrodes are properly placed onthe patient, (b) a defibrillator control box, connected to theelectrodes, constructed to analyze data received from the electrodes andto measure the time elapsed since the defibrillator control box wasactivated by the caregiver and/or since the last shock was delivered tothe patient; and (c) a user interface constructed to display informationconcerning the appropriate step of the resuscitation sequence to beperformed by the caregiver at a particular time, based on the datareceived from the electrodes and the elapsed time.

[0021] In yet another aspect, the invention features a defibrillatorincluding: (a) electrodes configured to be attached to a patient, toacquire data indicative of the patient's heart rhythm and to deliver adefibrillating shock if appropriate; (b) a defibrillator control boxconnected to the electrodes; (c) a treatment button configured to bepressed by a caregiver to deliver a defibrillating shock, the locationof the treatment button being indicated by a heart symbol; and (e)electronics configured to cause the heart symbol to be temporarilyilluminated if a shock is advised based on ECG analysis performed by thedefibrillator control box.

[0022] In preferred implementations, the graphical interface illustratesthe entire sequence of resuscitation activities that are recommended bythe American Heart Association. As a result, the graphical interfacehelps both experienced and novice users to get through the early stepsof patient care that are included in the AHA's resuscitation protocols.

[0023] Moreover, because “a picture is worth a thousand words”, thegraphical interface reminds the caregiver of how the steps in the AHA'sresuscitation protocols should be performed. For example, rather thansimply prompting the caregiver to “check airway”, the graphicalinterface reminds the caregiver that this means that the caregivershould perform the head-tilt chin lift maneuver. To provide the sameinformation using audio or textual prompts alone could inundate the caregiver with detailed information that could confuse the caregiver. Thegraphical interface allows the caregiver to use his or her visual sensesin order to remember what to do at each step during the rescue. Thepictures may, also, be helpful when the rescue is being performed in anoisy environment when voice prompts may be hard to hear.

[0024] Other features and advantages of the invention will be apparentfrom the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

[0025]Fig. 1 is a perspective view of an AED with its cover on.

[0026]FIG. 2 is a perspective view of the AED of FIG. 1 with the coverremoved.

[0027]FIG. 3 is a plan view of the graphical interface decal used on thecover of the AED of FIG. 1.

[0028]FIG. 4 is a plan view of the graphical interface decal used on thecontrol box of the AED of FIG. 1, as shown in FIG. 2.

[0029]FIG. 5 is a flow chart indicating audio prompts provided duringuse of the AED of FIG. 1 and steps to be performed by the caregiver inresponse to the graphical and audio prompts.

[0030]FIG. 6 is a plan view of a graphical interface decal used on theunderside of the cover of the AED of FIG. 1.

DETAILED DESCRIPTION

[0031] Referring to FIG. 1, an automated external defibrillator 10includes a removable cover 12 and a control box 14. The defibrillator 10is shown with cover 12 removed in FIG. 2. An electrode assembly 16 (or apair of separate electrodes) is connected to the control box 14 by acable 18. Electrode assembly 16 is stored under cover 12 when thedefibrillator is not in use.

[0032] Control box 14 includes a power button 15 and a status indicator17. Status indicator 17 indicates to the caregiver whether thedefibrillator is ready to use.

[0033] The cover 12 includes a cover decal 20 (FIGS. 1 and 3) includinga logo 22 and a series of graphics 24, 26 and 28. Logo 22 may provideinformation concerning the manufacturer of the device and that thedevice is a defibrillator (e.g., “Zoll AED”, as shown in FIG. 3,indicating that the device is a Semi-automatic External Defibrillatoravailable from Zoll Medical). Graphics 24, 26 and 28 lead the caregiverthrough the initial stages of a cardiac resuscitation sequence asoutlined in the AHA's AED treatment algorithm for Emergency Cardiac Carepending arrival of emergency medical personnel . (See “Guidelines 2000for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.Supplement to Circulation,” Volume 102, Number 8, Aug. 22, 2000, pp.1-67.) Thus, graphic 24, showing the caregiver and patient, indicatesthat the caregiver should first check the patient for responsiveness,e.g., by shaking the patient gently and asking if the patient is okay.Next, graphic 26, showing a telephone and an emergency vehicle,indicates that the caregiver should call for emergency assistance priorto administering resuscitation. Finally, graphic 28 indicates that afterthese steps have been performed the caregiver should remove the lid 12of the defibrillator, remove the electrode assembly 16 stored under thelid, and turn the power on by depressing button 15. The graphics arearranged in clockwise order, with the first step in the upper left,since this is the order most caregivers would intuitively follow.However, in this case the order in which the caregiver performs thesteps is not critical, and thus for simplicity no other indication ofthe order of steps is provided.

[0034] The cover may also include a slot 28 (FIG. 1), through which acard bearing local emergency information can be inserted and atransparent window 30, communicating with slot 28, through which thecard can be viewed. Alternatively, or in addition, this information canbe displayed on a decal to be applied to the cover by a user, e.g.,phone number decal 32 (FIG. 1) applied to area 34 (FIG. 3) of coverdecal 20. These features allow the emergency information to becustomized for a particular location and to be easily updated if changesoccur.

[0035] The control box includes a control box decal 40, shown in FIGS. 2and 4. Decal 40, like decal 20, includes a series of graphics 42-49(FIG. 4). In this case, the graphics are configured to lead thecaregiver through the entire resuscitation sequence, as will beexplained below with reference to FIG. 5. Decal 40 also includes acenter graphic 50, which includes representations of a hand 52 and aheart 54 (FIG. 4). Center graphic 50 overlies a treatment button which,when depressed, causes the defibrillator to deliver a defibrillatingshock to the electrode assembly 16.

[0036] Each of the graphics on control box decal 40 is accompanied by alight source that can be temporarily illuminated to indicate that theilluminated step should be performed at that particular time. Theselight sources guide the caregiver, step-by-step, through theresuscitation sequence, indicating which graphic should be viewed ateach point in time during resuscitation.

[0037] The light source for each of the graphics 42-49 is preferably anadjacent LED (LEDs 56, FIG. 2). The heart 54 may be translucent andbacklit by a light source in the control box (not shown). Alternatively,the heart 54 may include an adjacent LED (not shown) and/or the hand 52may include an LED 57 as shown.

[0038] LEDs 56 and 57 are mounted on the control box and are visiblethrough openings in the decal 40. When the heart 54 and/or hand 52 isilluminated, this indicates to the caregiver that the underlyingtreatment button should be depressed to administer a defibrillatingshock, as will be discussed in further detail below.

[0039] Programmable electronics within the control box 14 are used todetermine when each of the light sources should be illuminated.

[0040] The illumination and subsequent turning off of the LEDs adjacentto graphics 42-45 is based on the amount of time that has elapsed sincethe caregiver turned the power on by depressing button 15. The elapsedtime is measured by the programmable electronics and used to illuminateeach of the LEDs associated with graphics 42-45 in turn. A time lapse ofabout 2 to 15 seconds is allowed between each illumination, to allow thecaregiver an appropriate amount of time to perform each step. These timeintervals vary from a few seconds for graphic 42 (check responsiveness)to 10 or more seconds for graphic 44 (open airway, check for breathing).

[0041] The illumination of the LED adjacent to graphic 46 is based onthe elapsed time, while the subsequent turning off of this LED is basedon whether the impedance measured by the programmable electronicsindicates that the electrodes of electrode assembly 16 have beencorrectly positioned on the patient. This LED remains lit until thecorrect impedance between the electrodes is detected, e.g., an impedanceof less than 300 ohms.

[0042] The illumination and turning off of the LEDs adjacent to graphics47-49, and of the light behind heart 54, is based on ECG data that isacquired by electrode assembly 16 and analyzed by the programmableelectronics, as will be discussed below with reference to FIG. 5.

[0043] The programmable electronics may also provide audio prompts,timed to coincide with the illumination of the light sources, as willalso be discussed below with reference to FIG. 5.

[0044]FIG. 5 illustrates, in flow chart form, the use of the graphics ondecal 40, and accompanying visual and audio prompts, by a caregiverperforming resuscitation. The text in boxes indicates steps performed bythe caregiver. The text in caption balloons, with ear symbols, indicatesaudio prompts generated by the defibrillator.

[0045] Thus, when a person collapses and a caregiver suspects that theperson is in cardiac arrest (100), the caregiver first gets thedefibrillator and turns the power on (102). If the unit passes itsinternal self tests, and is ready for use, this will be indicated byindicator 17, as discussed above. Next, the defibrillator prompts thecaregiver with an introductory audio message, e.g., “Stay calm. Listencarefully.” (Audio prompt 104.)

[0046] Shortly thereafter, the defibrillator will prompt the caregiverwith an audio message indicating that the caregiver should check thepatient for responsiveness (audio prompt 106). Simultaneously, the LEDadjacent graphic 42 will light up, directing the caregiver to look atthis graphic. Graphic 42 will indicate to the caregiver that she shouldshout “are you OK?” and shake the person (step 108) in order todetermine whether the patient is unconscious or not.

[0047] After a suitable period of time has elapsed (e.g., 2 seconds), ifthe caregiver has not turned the defibrillator power off (as would occurif the patient were responsive), the defibrillator will give an audioprompt indicating that the caregiver should call for help (audio prompt110). Simultaneously, the LED adjacent graphic 42 will turn off and theLED adjacent graphic 43 will light up, directing the caregiver'sattention to graphic 43. Graphic 43 will remind the caregiver to callemergency personnel (step 112), if the caregiver has not already doneso.

[0048] After a suitable interval has been allowed for the caregiver toperform step 112 (e.g., 2 seconds since audio prompt 110) thedefibrillator will give an audio prompt indicating that the caregivershould open the patient's airway and check whether the patient isbreathing (audio prompt 114). The LED adjacent graphic 43 will turn off,and the LED adjacent graphic 44 will light up, directing the caregiver'sattention to graphic 44, which shows the proper procedure for opening apatient's airway. This will lead the caregiver to lift the patient'schin and tilt the patient's head back (step 116). The caregiver may alsoposition an airway support device under the patient's neck andshoulders, if desired, as discussed below with reference to FIG. 7. Thecaregiver will then check to determine whether the patient is breathing.

[0049] After a suitable interval (e.g., 15 seconds since audio prompt114), the defibrillator will give an audio prompt indicating that thecaregiver should check for signs of circulation (audio prompt 118), theLED adjacent graphic 44 will turn off, and the LED adjacent graphic 45will light up. Graphic 45 will indicate to the caregiver that thepatient should be checked for a pulse or other signs of circulation asrecommended by the AHA for lay rescuers (step 120).

[0050] After a suitable interval (e.g., 5 to 7 seconds since audioprompt 118), the defibrillator will give an audio prompt indicating thatthe caregiver should attach electrode assembly 16 to the patient (audioprompt 122), the LED adjacent graphic 45 will turn off, and the LEDadjacent graphic 46 will light up. Graphic 46 will indicate to thecaregiver how the electrode assembly 16 should be positioned on thepatient's chest (step 124). The defibrillator will periodically repeataudio prompt 122 every 15 seconds until the electrodes are properlyconnected to the patient.

[0051] When the impedance data received from the electrode assemblyindicates that the electrodes are properly positioned and in contactwith the patient's skin, the defibrillator will stop audio prompt 122and turn off the LED adjacent graphic 46. At this point, the LEDadjacent graphic 47 will light up, and the defibrillator will give anaudio prompt indicating that the patient's heart rhythm is beinganalyzed by the defibrillator and the caregiver should stand clear(audio prompt 126). While this LED is lit, the defibrillator willacquire ECG data from the electrode assembly, and analyze the data todetermine whether the patient's heart rhythm is shockable. This analysisis conventionally performed by AEDs.

[0052] If the defibrillator determines that the patient's heart rhythmis not shockable, the defibrillator will give an audio prompt such as“No shock advised” (audio prompt 128). The LEDs next to graphics 48 and49 will then light up, and the defibrillator will give an audio promptindicating that the caregiver should again open the patient's airway,check for breathing and a pulse, and, if no pulse is detected by thecaregiver, then commence giving CPR (audio prompt 130, step 132).Graphics 48 and 49 will remind the caregiver of the appropriate steps toperform when giving CPR.

[0053] Alternatively, if the defibrillator determines that the patient'sheart rhythm is shockable, the defibrillator will give an audio promptsuch as “Shock advised. Stand clear of patient. Press treatment button.”(Audio prompt 134.) At the same time, the heart 54 and/or hand 52 willlight up, indicating to the caregiver the location of the treatmentbutton. At this point, the caregiver will stand clear (and warn others,if present, to stand clear) and will press the heart 54, depressing thetreatment button and administering a defibrillating shock (or a seriesof shocks, as determined by the defibrillator electronics) to thepatient (step 136).

[0054] After step 136 has been performed, the defibrillator willautomatically reanalyze the patient's heart rhythm, during which audioprompt 126 will again be given and graphic 47 will again be illuminated.The analyze and shock sequence described above will be repeated up tothree times if a shockable rhythm is repeatedly detected or until thedefibrillator is turned off or the electrodes are removed. After thethird shock has been delivered, the device will illuminate LEDs 48 and49 and issue the audio prompts 130/132. The device will keep LEDs 48 and49 illuminated for a period of approximately one minute indicating thatif CPR is performed, it should be continued for the entire minute.“Continue CPR” audio prompts may be repeated every 15-20 seconds duringthis period to instruct the user to continue performing chestcompressions and rescue breathing.

[0055] After approximately one minute has elapsed, the device willextinguish LEDs 48 and 49 and illuminate LED 47. Audio prompt 126 (standclear, analyzing rhythm) will also be issued and a new sequence of up tothree ECG analyses/shocks will begin.

[0056] If the caregiver detects circulation during step 132, thecaregiver may turn off the defibrillator and/or remove the electrodes.Alternatively, the caregiver may not perform further CPR, butnonetheless allow the device to reanalyze the ECG after each one minuteCPR period in order to provide repeated periodic monitoring to ensurethe patient continues to have a non-shockable rhythm.

[0057] Thus, in the continuing presence of a shockable rhythm, thesequence of three ECG analyses and three shocks, followed by one minuteof CPR, will continue indefinitely. If, instead, a non-shockable rhythmis or becomes present, the sequence will be analyze/no shock advised,one minute of CPR, analyze/no shock advised, one minute of CPR, etc.When a shock is effective in converting the patient's heart rhythm to aheart rhythm that does not require further defibrillating treatment, thesequence will be: analyze/shock advised, shock (saves patient),analyze/no shock advised, one minute CPR period (if pulse is detectedthen caregiver will not do CPR during this period), analyze/no shockadvised, one minute CPR period, etc., continuing until the caregiverturns the defibrillator (e.g., if the caregiver detects a pulse) or theelectrodes are removed.

[0058] If electrode contact is lost at any time (as determined by theimpedance data received from the electrode assembly), this will resultin an appropriate audio prompt, such as “check electrodes” andillumination of the LED adjacent graphic 46.

[0059] Other embodiments are within the scope of the following claims.

[0060] For example, the graphics on the center decal can be accompaniedby any desired light source. For instance, if desired, all of thegraphics can be translucent, and can be backlit. Alternatively, thegraphics can be provided in the form of LED images, rather than on adecal.

[0061] While it is generally preferred that audio prompts and visual(light source) prompts be used, these features may be omitted ifdesired.

[0062] Moreover, while the electrodes have been illustrated in the formof an integral electrode assembly, separate electrodes may be used.

[0063] In preferred implementations, generally all of the graphicallyillustrated steps are shown at the same time, e.g., as illustrated bythe decal described above. This arrangement allows the caregiver to seethe steps that will be performed next and thus anticipate the next stepand begin it early if possible. However, alternatively, the graphics canbe displayed one at a time, e.g., by using a screen that displays onegraphic at a time or backlit graphics that are unreadable when not backlit. This arrangement may in some cases avoid overwhelming novice or layrescuers, because it does not present the caregiver with too muchinformation all at the same time.

[0064] If desired, each graphic could have an associated button which,when pressed, causes more detailed audio prompts related to that graphicto be output by the defibrillator.

[0065] The cover 12 of the AED may include a decal on its underside,e.g., decal 200 shown in FIG. 7. Decal 200 illustrates the use of thecover as a passive airway support device, to keep the patient's airwayopen during resuscitation. Graphic 202 prompts the caregiver to roll thepatient over and place cover 12 under the patient's shoulders, andgraphic 204 illustrates the proper positioning of the cover 12 under thepatient to ensure an open airway.

[0066] While such a graphic is not included in the decal shown in FIG.4, the decal 40 may include a graphic that would prompt the user tocheck to see if the patient is breathing. Such a graphic may include,e.g., a picture of the caregiver with his ear next to the patient'smouth. The graphic may also include lines indicating flow of air fromthe patient's mouth.

[0067] “Illuminated”, “light up”, and similar terms are used herein torefer to both a steady light and a blinking light. A blinking light maybe used, if desired, to more clearly draw the user's attention to theassociated graphic.

What is claimed is:
 1. A defibrillator comprising: electrodes configuredto be attached to a patient, to acquire data indicative of the patient'sheart rhythm and to deliver a defibrillating shock if appropriate; adefibrillator control box connected to the electrodes; and on a portionof the defibrillator control box, a series of graphics configured toprompt a caregiver to perform a sequence of steps appropriate fortreating a victim of suspected cardiac arrest.
 2. The defibrillator ofclaim 1 wherein the graphics include a picture configured to prompt thecaregiver to check the patient for responsiveness.
 3. The defibrillatorof claim 1 wherein the graphics include a picture configured to promptthe caregiver to call for emergency assistance.
 4. The defibrillator ofclaim 1 wherein the graphics include a picture configured to prompt thecaregiver to open the patient's airway.
 5. The defibrillator of claim 4wherein the picture illustrates how to open the patient's airway.
 6. Thedefibrillator of claim 1 wherein the graphics include a pictureconfigured to prompt the caregiver to check the patient for signs ofcirculation.
 7. The defibrillator of claim 1 wherein the graphicsinclude a picture configured to prompt the caregiver to attach theelectrodes to the patient.
 8. The defibrillator of claim 7 wherein thepicture illustrates where the electrodes should be attached.
 9. Thedefibrillator of claim 1 wherein the graphics include a pictureconfigured to prompt the caregiver to stand clear of the patient. 10.The defibrillator of claim 1 wherein the graphics include a pictureconfigured to prompt the caregiver to press a treatment button to causethe defibrillator to administer a defibrillating shock.
 11. Thedefibrillator of claim 1 wherein the graphics include a pictureconfigured to prompt the caregiver to perform CPR.
 12. The defibrillatorof claim 1 wherein the graphics include pictures illustrating proceduresfor chest compressions and rescue breathing.
 13. The defibrillator ofclaim 10 wherein the picture includes a heart symbol indicating thelocation of the treatment button.
 14. The defibrillator of claim 1further comprising a treatment button configured to be pressed by thecaregiver to cause the defibrillator to administer a defibrillatingshock.
 15. The defibrillator of claim 1 further including a light sourceassociated with each of the graphics in the series.
 16. Thedefibrillator of claim 15 further comprising electronics configured tosequentially illuminate the light sources.
 17. The defibrillator ofclaim 16 wherein the graphics include one or more pictures selected fromthe group consisting of: a picture configured to prompt the caregiver tocheck the patient for responsiveness; a picture configured to prompt thecaregiver to call for emergency assistance; a picture configured toprompt the caregiver to open the patient's airway; a picture configuredto prompt the caregiver to check the patient for signs of circulation; apicture configured to prompt the caregiver to attach the electrodes tothe patient; a picture configured to prompt the caregiver to stand clearof the patient; and a picture configured to prompt the caregiver toperform CPR.
 18. The defibrillator of claim 16 wherein the graphicsinclude a picture configured to prompt the caregiver to press atreatment button to cause the defibrillator to administer adefibrillating shock.
 19. The defibrillator of claim 16 furthercomprising electronics configured to measure the time elapsed from thetime at which the caregiver turned the power on to activate thedefibrillator, and at least some of the light sources are sequentiallyilluminated based on the elapsed time.
 20. The defibrillator of claim 16further comprising electronics configured to be preprogrammed with timesfor the illumination of the light sources, the times being based on apredetermined algorithm.
 21. The defibrillator of claim 19 or 20 whereinthe graphics include one or more pictures selected from the groupconsisting of: a picture configured to prompt the caregiver to check thepatient for responsiveness; a picture configured to prompt the caregiverto call for emergency assistance; a picture configured to prompt thecaregiver to open the patient's airway; a picture configured to promptthe caregiver to check the patient for signs of circulation; a pictureconfigured to prompt the caregiver to attach the electrodes to thepatient; a picture configured to prompt the caregiver to stand clear ofthe patient; and a picture configured to prompt the caregiver to performCPR.
 22. The defibrillator of claim 16 further comprising electronicsconfigured to acquire data from the electrodes, and at least some of thelight sources are sequentially illuminated based on the data acquiredfrom the electrodes.
 23. The defibrillator of claim 16 wherein at leastsome of the light sources are sequentially illuminated based on the timeelapsed from the time at which a shock was last delivered to thepatient.
 24. The defibrillator of claim 15 wherein the light sourcescomprise LEDs.
 25. The defibrillator of claim 1 further comprisingelectronics configured to provide audio prompts to the caregiver. 26.The defibrillator of claim 25 wherein the audio prompts are associatedwith the series of graphics and are given sequentially to guide thecaregiver through the sequence of steps.
 27. The defibrillator of claim15 further comprising electronics configured to provide audio prompts tothe caregiver.
 28. The defibrillator of claim 27, further comprisingelectronics configured to sequentially illuminate the light sources,wherein the audio prompts are associated with the series of graphics andwith the sequential illumination of the light sources, to guide thecaregiver through the sequence of steps.
 29. The defibrillator of claim26 or 28 further comprising electronics configured to measure the timeelapsed from the time at which the caregiver turned the power on toactivate the defibrillator, and at least some of the audio prompts aretimed to occur based on the elapsed time.
 30. The defibrillator of claim26 or 28 further comprising electronics configured to acquire data fromthe electrodes, and at least some of the audio prompts are timed tooccur based on the data acquired from the electrodes.
 31. Thedefibrillator of claim 26 or 28 wherein at least some of the audioprompts are timed to occur based on the time elapsed from the time atwhich a shock was last delivered to the patient.
 32. The defibrillatorof claim 1 wherein at least some of the graphics are provided on a coverportion of the defibrillator control box.
 33. The defibrillator of claim1 wherein at least some of the graphics are provided on the outside ofthe cover portion of the defibrillator.
 34. The defibrillator of claim33 wherein the graphics on the cover portion include a pictureindicating that the cover should be removed from the defibrillator. 35.The defibrillator of claim 33 wherein the cover portion includes a spaceprovided for local emergency information.
 36. The defibrillator of claim35 wherein the cover portion includes a window behind which a cardbearing local emergency information can be placed.
 37. The defibrillatorof claim 1 wherein at least some of the graphics are provided in theform of backlit, translucent images.
 38. The defibrillator of claim 1wherein at least some of the graphics are provided in the form of anelectronic display.
 39. The defibrillator of claim 1 wherein at leastsome of the graphics are provided in the form of a decal.
 40. Thedefibrillator of claim 1 further comprising buttons, associated with atleast some of the graphics, which, when pressed, cause more detailedaudio prompts related to the associated graphic to be output by thedefibrillator.
 41. A system for prompting a care giver in aresuscitation sequence for a patient who may b e suffering from cardiacarrest, comprising electrodes constructed to acquire data, indicative ofthe heart rhythm of the patient and indicative of whether the electrodesare properly placed on the patient, a defibrillator control box,connected to the electrodes, constructed to analyze data received fromthe electrodes and to measure the time elapsed since the defibrillatorcontrol box was activated by the caregiver and/or since the last shockwas delivered to the patient; and a user interface constructed todisplay information concerning the appropriate step of the resuscitationsequence to be performed by the caregiver at a particular time, based onthe data received from the electrodes and the elapsed time.
 42. Adefibrillator comprising: electrodes configured to be attached to apatient, to acquire data indicative of the patient's heart rhythm and todeliver a defibrillating shock if appropriate; a defibrillator controlbox connected to the electrodes; a treatment button configured to bepressed by a caregiver to deliver a defibrillating shock, the locationof the treatment button being indicated by a heart symbol; andelectronics configured to cause the heart symbol to be temporarilyilluminated if a shock is advised based on ECG analysis performed by thedefibrillator control box.
 43. The defibrillator of claim 1 wherein thegraphics include one or more pictures indicating that the caregivershould place a passive airway support under the shoulders of thepatient.
 44. The defibrillator of claim 1 wherein the graphics include apicture configured to prompt the caregiver to check to see if thepatient is breathing.
 45. The defibrillator of claim 20 wherein thealgorithm takes into account one or more of the following items of data:(a) the time elapsed from the time at which the previous light source inthe sequence was first illuminated, and/or (b) the time elapsed from thelast time a shock was delivered to the patient, and/or (c) the resultsof ECG analysis.
 46. The defibrillator of claim 26 or 28 furthercomprising electronics configured to be preprogrammed with times for thegeneration of the audio prompts, the times being based on apredetermined algorithm.
 47. The defibrillator of claim 46 wherein thealgorithm takes into account one or more of the following items of data:(a) the time elapsed from the time at which the previous light source inthe sequence was first illuminated, and/or (b) the time elapsed from thelast time a shock was delivered to the patient, and/or (c) the resultsof ECG analysis.